Internal-combustion engine.



W. L-. DEMPSEY.

INTERNAL COMBUSTION ENGINE. APPLICAIIOH FILED FEB. 26. 1916.

1,261,779. Patented Apr. 9, 1918.

2 SHEETS-SHEET I.

lnvenTor.

William L'. Dempsey by fmd MkM A'rTys.

W. L. DE MPSEY.

INTERNAL COMBUSTION ENGINE.

APPLICATION mu) FEB. 2b. 191s.

Patented Apr. 9, 1918.

2 SHEETSSHEET 2- lnvenror.

WiHiom L. Dempsey y z/m MkW ATTys.

WILLIAM L. DEMPSEY, 0F SOMERVILLE, MASSACHUSETTS.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented Apr, 5%, i918.

Application filed February 26, 1916. Serial No. 80,735.

To all whom it may concern:

Be it known that 1, WILLIAM L. DEMPSEY, a citizen of the United States, and resident of Somerville, county of Middlesex, State of Massachusetts, have invented an Improvement in Internal-Combustion Engines, of which the following description, in connection with the accompanying drawing, is a specification, like characters on the drawing representing like parts.

This invention relates to improvements in internal combustion engines and comprises the utilization of a novel process or c cle of operations adapted to increase the e ciency of an internal combustion engine when used with any kind of fluid over that of the usual engine and also to adapt the engine for use with a variety of hydrocarbons ranging from the lighter gasolene or benzin to kerosene and other heavier oils.

The essential conditions for the successful working of an internal combustion engine comprise:

1. The combining of the fuel and air components of the charge in proper proportions to give an explosive mixture of highest power producing value,

2. The introduction of a full charge of explosive having proper proportions of fuel and oxygen into the working cylinder by the charging stroke of the piston,

3. The application of a proper amount of compression,

4. The ignition of the compressed charge at the proper time in the cycle of operations,

5.The complete combustion of the fuel component and the utilization of the resulting pressure practically to the end of the power stroke of the piston, and,

6. The thorough scavenging of the cylinder of the products of combustion prior to the admission of a fresh charge.

in the usual type of engines there is an insufficiency of oxygen introduced into a mixture with the fuel to cause a complete combustion of the fuel as is demonstrated by the fact that the carbon deposits have to be burned out of the cylinders of engines quite frequently in order to keep the engine in efiicient running condition, particularly n here a heavy oil such as kerosene or crude oil is used.

The presentinvention which embodies in part the principle disclosed in my Patentv No. 1,176,207 granted March 21, 1916 is devised to avoid this objection by i'orcing into the cylinder of the engine after the fuel charge has been introduced, an amount of oxygen in addition to that which is carried in with the fuel suflicient properly to combine with an over-rich charge of fuel mix ture, and in properly mingling the oxygen thus introduced with the fuel so that upon ignition the same will instantly combine.

In the usual type of engines and particularly the four cycle type, the charge taken into the cylinder is below atmospheric pressure as is indicated by the cards taken from the cylinders of such engines, therefore the contents of the cylinder at the end of the charging stroke are less in volume than an amount of air at atmospheric pressure adapted to occupy the piston displacement plus the clearance space. By the introduction of an additional amount of atmosphere as above suggested in combination with the introduction of an overrich mixture 1 have been able to obtain a charge of greater specific gravity than is usual in engines of thlS type,

One of the most detrimental conditions which result in the reduction of a proper charge in explosive engines, particularly those in which kerosene or other heavier oils are used, arises from the fact that the process of vaporization. requires the raising of the temperature of the oil vapor and the air with which it is mixed to a temperature ranging from 250 to 300 T As a result the specific gravity or the charge is greatly reduced so that a given volume contains a smaller number of thermal units than when it is at atmospheric temperature. Furthermorethe consequent high initial tempera ture results in a higher compression temperature so that there is a greater loss or heat through the cylinder Walls than. in case the charge is admitted to the cylinder at atmospheric temperature, so that a matter of fact engines ad r. to use kerosene or other heavier oils slow. a eiliciency than when GPQIz lone or other light oils, notwi as kcrosene or oil value,

fly the present invention greater temperature ran e the cylinder provided permitting" tie introduction of .a'heavier charge of fuel and followed by the mingling therewith of the proper quantity of oxygen.

bearing atmosphere so that the resultant power from the explosion rises to: a much higher efficiency than heretofore obtained.

. iln the majority ofengines the products of combustion or dead gases are not. completely swept away from the cylinder during the" exhaust stroke of the pistonso that thereis a' considerablefamount of inert gas. within the cylinder at the moment of explosion. This of course reduces theefliciencyof the ythe present process or cycle and the apparatusv design edfor its employment, means are provided whereby alarge'. quantity of compressed fresh air isintroduced into the cylinder at the end of .the'power stroke so that. it thoroughly scaven es the cylinder upon the exhaust stroke, t is air preferablybeing cooledat the same time by a spray of'water so that the temperature 'of the cylinder, and of the piston is materially reduced and awider range of temperature in the cylinder 'as' above referred to obtained.

In brief, my invention comprises the utilization of a novel series of incidents in an internal combustion engine of the four stroke type which amounts in effect to a six cycle operation in the usual four cycle type of engine, these incidents being as follows: l. The drawing into the cylinder by the intake stroke of the piston, through a ,valve preferably located near the endof the cylinder, of .a hydrocarbon mixture at with air, overrich in hydrocarbon. I,

2. In forcin into the cylinder at the inner end of t e suction stroke an additional amount of air or air'combined with water, thereby increasing. the volume and pressure with n the cylinder, the inlet valve for the mixture in the meantime having been closed. I

3. Compressing the mixture upon the return stroke ofthe piston.

4. Igniting the mixture .and causing the expansion produced thereby to drive the piston on its working stroke.

5. Exhaustingthe products of combustion from the cylinder, preferably through a 'valve in or near the. head thereof slightl illustratin gravity than V has lowering the initial compression temperature,

4th, more thoroughly to scavenge the cylinder and thereby increase itsthermal and mechanical efficiency.

Any suitable apparatus may-be employed to produce the succession of incidents or cycle above described. In fact the usual type of four stroke combustion engine of the character usually known as the'four cycle type may be adapted with very slight modifications to accomplish the purpose herein set forth.

The drawin s illustrate conventional-1y a usual form of our stroke engine embodying my invention, the six fi res of the drawing the successive positions of the piston wit in the cylinder and the arrangemehtof parts required to'produce the rcsults above described.

In the drawings:

Figure 1 is a vertical sectional view through the cylinder and crank case of the engine showing the iston receding from the cylinderhead durlng the intake stroke,

2 is a similar view showing the piston at; the end of the intake stroke and air and water being forced into the cylinder,

Fig. 3 shows the cylinder upon its compression stroke,

Fig. 4 shows the piston traveling under the influence of the exploding gases of the working stroke,

Fig. 5 is a similar view showin the piston at the end of the working stro, e, the exhaust valve being opened and air and water being admitted into the cylinder at the end of the stroke, and,

Fig. 6 shows the beginning of the exhaust stroke, air and water having been forced into the cylinder for the purpose of scavenging the cylinder of burnt gases and reducing the temperature of the cylinder and piston.

The internal combustion engine illustratedin the accompanying drawings comprises the usual base 1 having an integral crank shaft casing 2 provided with suitable journals, not shown, for the crank shaft 3. a fly wheel 4 being attached to the crank shaft in the usual manner. The cylinder 5 preferably is open at one end to communicate wlththe crank case chamber and is provided with a flange (3 by which it is securely bolted to a seat '7 upon the crank case. The cylinder desirably is formed with the usual water jacket 8 which may be integral with the walls of' the cylinder and is provided also with the usual inlet 9 for the fuel mixture. and with the usual exhaust chamber 10.

The fuel inlet 9 and the exhaust chamber 10 preferably connect with the combustion chamber 11 of the cylinder respectively through ports 12 and 13 located in the head of the cylinder thereby providing a construction in which the clearance space in the end of the cylinder may be reduced as far as practicable.

Suitable valves 14 and 15 are provided to close the inlet and exhaust ports leading into the explosion chamber 11 said valves being operated from the crank shaft of the engine in properly timed relation as hereinafter described through the usual links and levers (ndt shown.)

The combustion chamber 11 is fitted with a piston 16 connected by a link 17 with the usual crank 18 which may be formed integral with the crank shaft. The forward end of the piston preferably is provided with a curved or crowned end 19 adapted to spread a jet of water introduced into the cylinder at the end of the piston stroke through a port 20 which may lead from the water jacket through the cylinder casing and which may be controlled by a needle valve 21. It will be understood that if desired the water which is introduced into the cylinder may be supplied from an independent source in any usual manner.

In order to introduce an additional amount of'air after the fuel laden mixture is introduced into the cylinder during the suction stroke of the piston a conduit 22. leading from the chamber in the crank case may be connected to a port 23 leading through the wall of the cylinder, preferably approximately at the limit of the travel of the piston in its exhaust and working strokes.

A check valve 24 preferabl is provided in the conduit 22 to prevent back pressure in the event that the exhaust valves are sluggish or improperly timed.

The crank case 2 is preferably formed to provide an air-tight chamber 25, a puppet valve 26 located at a convenient point in the crank case permitting air to be drawn into the chamber 25 upon the forward stroke of the piston as is usual in machines of the type illustrated. Itwill however be understood that separate mechanism may be provided if desired for compressing the air which is to he introduced into the cylinder in the manner described.

in the operation of the engine above described a fuel laden mixture, preferably overrich in hydrocarbon is introduced into the combustion chamber upon the charging stroke as illustrated in Fig. 1, the valve 1d in the inlet port being opened as illustrated. As the piston approximately reaches the end of the chargin stroke, the valve M is closed as indicated in Fig. 2 and the port '13 uncovered by the end of the piston, thus permitting the air which is compressed in the crank case during the charging stroke of the piston to bev forced through the conduit 23 into the combiistion chamber, thus supplying to the mixture therein an additional amount of cool air. I This air, and also the walls of the cylinder maybe further cooled by the introduction of water throughthe port 20 leading from the water jacket or other water supply to the cylinder, said port being opened when the end of the piston passes beyond the same. The piston 19 is 'so positioned that when the port 20 is opened the jet of water which is forced into the combustion chamber will impinge upon the curved face thereby andbe broken into a spray. The spray thus formed will be further atomized by the inrushing air through the conduit 22 and the port 23 which is located practically opposite so that the air and water will be thoroughly commingled with the explosive mixture introduced through the inlet port. By this means a sufiicient amount of oxygen will be introduced to produce a C0111- plete combustion with the hydrocarbon of the mixture even though the latter is overrich in fuel. i

It will be observed that the period during which the power and water is thus introduced is relatively long since the crank at that time is passing dead center so that an ample amount of air may be introduced under pressure to raise the pressure within the combustion chamber considerably above atmospheric pressure.

After the crank passes over dead center the piston again travels forward as illustrated in Fig. 3, compressing the mixture in the forward end of the cylinder, the

water port 20 and air port 23 being at this time closed by the piston. When the piston has reached its forward stroke the contents of the combustion chamber are ignited and the piston forced backwardly upon its working stroke as illustrated in Fig. 5. As the piston approaches and almost reaches the end of its working stroke the valve15 is opened by suitable mechanism not shown and at about the same time the end of the piston uncovers the air port 23 and the water port 20 so that, as the crank again reaches dead center, air is forced into the combustion chamber through the conduit 22 and port 23, thus serving to force the products of combustion out of the combustion chamber 11. At the same time the water introduced through the water port 20 in conjunction with the cool air introduced through the port 23 serves to reduce the temperature of the cylinder to a great extent.

As the piston moves forward in its final exhaust stroke it is preceded by a strata of pure air so that by the time it reaches the forward limit of its stroke all of the products of combustion will have been forced through the exhaust port 13 and the cylinder will be ready to receive a fresh charge upon the succeeding charging stroke of the piston. 7

It is well known that the fuel consumption of an engine running upon a light load is greatlv in excess of the proportional amount of fuel consumed when running upon a full load and this would be especiall y true of the engine embodying my improvements wherein an overrich charge of fuel is introduced into the cylinder upon each chargin stroke of the engine, and

supplemented by the introduction of an ad-' ditional amount of air. In order to provide means whereby the engine may be run under a light load at greater efliclency 1t is therefore desirable that the supply of additional fuel and air to the cylinder may be eliminated and to this end I haveplaced in the conduit leading from the crank case to the combustion chamber of the cylinder a two way valve 27 by means of which connection may be made directly from the crank case to the cylinder or which may be so positioned as to open the crank case directl to the atmosphere so that when it is desired to run under a light load the conduit to the combustion chamber will be closed and at the same time the crank case chamber shall be open to the air. lrVhen under a light load the fuel supply Will be cut down by regulation of the needle valve in the usual manner.

Any form of two way valve may be employed in the conduit 22 such as that illustrated herein which comprises the usual cylindrical valve having a port extending directly through the same with a communicating port at right angles thereto or it may be in the form of a flap valve pivoted at the division of the main conduit pipe 22 and the lateral extension 252* thereof, the valve being adapted to close either the passage leading to the cylinder or that leading to the atmosphere.

By this construction the engine is in effect a duplex engine adapted to work economically under widely different conditions so that a relatively light engine may be used to perform a great amount of work under a heavy load condition with greater economy than any engine heretofore constructed and may also be adapted to carry a light load at the same relative efficiency as if running under a. full load.

By reason of this construction therefore "a relatively light engine is provided which It will be understood that any suitable apparatus may be utilized to produce the cycle of operations herein described, that the apparatus shown diagrammatically in the drawings is merely illustrative of a simple type of engine to which the principles of my'invention may be applied and that the following claims are intended to cover any type of apparatus which may be utilized to produce the successive incidents of operation or cycles herein described.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. The process of producing work from an internal combustion engine comprising a cylinder with a piston reciprocable therein; which consists in supplying the cylinder during the charging stroke of the piston with an over-rich charge of explosive mixture, forcing cool air under pressure into said cylinder andsimultaneously introducing a jet of water into said cylinder at the end of the charging stroke thereby increasing the specific gravity of the charge and supplying sufficient oxygen to the cylinder to cause complete combustion of the fuel, compressing the charge upon the return stroke of the piston, igniting the charge to impel the piston upon its working stroke and finally exhausting the products of combustion.

2. The process of producing workfrom an internal combustion engine comprising a cylinder With a piston reciprocable therein; which consists in supplying the cylinder during the charging stroke of the piston with an over-rich charge of explosive mixture. forcing cool air under pressureinto said cylinder and simultaneously introducing a jet of water into said cylinder in the path of the blast of air at the end of the charging stroke thereby increasing the specific gravity of the charge and supplying sufficient oxygen to the cylinder to cause complete combustion of the fuel, compressing the charge upon the return stroke of the piston, igniting the charge to impel the pis-' ton upon its work stroke and finally exhausting the products of combustion.

3. The process of producing work from an internal combustion engine comprising a cylinder with a piston reciprocable therein; which-consists in supplying the cylinder during the charging stroke of the piston with an over-rich charge of explosive mixture, forcing cool air under pressure into said cylinder at the end of the charging stroke thereby increasing the specific gravity of the charge and supplying sufiicient oxygen to the cylinder to cause complete combustion of the fuel, compressing the charge upon the return stroke of the piston, igniting the charge to impel the piston upon its work producing stroke, exhausting the cylinder slightly before the end of the working stroke and simultaneously forcing into the cylinder cool air under pressure and introducing a jet of waterin the path of the blast of air, thereby reducing the temperature of the cylinder and causing the products of combustion to be swept completely therefrom.

4. An internal combustion engine C0111- prising a cylinder, a piston reciprocable therein connected to the crank of a. crank shaft, means for supplying an explosive mixture upon the charging stroke of the piston, means for supplying air under pressure to said cylinder in advance of the end of the charging stroke and simultaneously supplying water thereto, whereby the temperature of the cylinder will be reduced, thereby permitting the introduction of an increased amount of air which will insure complete combustion.

5. An internal combustion engine comprising a cylinder, a piston reciproeably mounted therein, means for supplying a charge to said cylinder through the head thereof, air and water ports slightly in advance of the limit of the charging and power strokes of the piston and means for supplying compressed air and water to the cylinder through said orts.

6. An internal combustion engine comprising a cylinder, having a water jacket, a piston reciprocably mounted in said cylinder and means connecting the same to the crank of a crank shaft, means for supplying an explosive mixture to said cylinder, an air port in advance of the limit of the charging and power strokes, means for supplying compressed air through said port and a valve controlled port opening from said water jacket into said cylinder slightly in advance of said limit of the strokes of the piston.

7 An internal combustion engine comprising a cylinder having a Water jacket, a piston having a crowned end reciprocably mounted in said cylinder and means connecting the same to the crank of a crank shaft, means for supplying an explosive mixture to said cylinder, an air port in advance of the limit of the charging and power strokes, means for supplying compressed air through said port, a valve controlled port opening from said water jacket into said cylinder slightly in advance of said limit of the strokes of the piston whereby the crowned end of said piston will deflect the jet of water into the path of the blast of air.

3 An internal combustion engine comprising a frame including a closed crank case, a cylinder secured to and opening into said crank case,a piston reciprocably mounted in said cylinder and means connecting said piston to the crank of a crank shaft within said crank case, means for supplying an explosive mixture to said cylinder throughout the greater part of the charging stroke of the piston, a conduit leading from said crank case into said cylinder slightly in advance of the limit of said piston upon the power stroke, said piston being adapted to operate as a valve for the port of said conduit and means for supplying Water to said cylinder through a port located slightly in advance of the limit of the stroke of the piston.

In testimony whereof, I have signed my name to this specification.

VVILLIAH L, DEMPSEY. 

